Refrigerating apparatus



1961 J. H. HEIDORN REFRIGERATING APPARATUS Filed Nov. 9, 1959 INVENTOR. John H. Heidorn BY H15 ATTORNEY United States Patent Ofiice 3,006,160 Patented Oct. 31,1961

3,006,160 REFRIGERATING APPARATUS John H. Heidorn, Dayton, Ohio, assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Filed Nov. 9, 1959, Ser. No. 851,726

.' ,6 Claims. (Cl. 62-296) This invention relates to refrigerating apparatus and more particularly to a muffler for use in a refrigerant compressor or the like.

In automobile air conditioning systems the refrigerant compressor is adapted to be driven by the main car engine which varies in speed without any regard to refrigeration requirements. The wide variation in the compressor operating speed introduces a number of problems, one of which is that of providing a suitable muffler for the compressor discharge line which will operate efliciently at slow compressor speeds and yet not unduly restrict the fiow of the compressed gas at the higher engine speeds.

It is an object of this invention to provide an inexpensive and trouble free mufiler having a variable baffle means therein whereby changes in the operating speed of the compressor automatically causes a variation in the restriction afforded by the baflle means.

More specifically, it is an object of this invention to provide a muffier wherein a bafile is provided with a plurality of apertures through which the compressed refrigerant is required to flow and wherein certain of the apertures are normally closed by means of a yieldable element which moves away from the apertures in response to a predetermined increase in refrigerant flow.

These and further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawing wherein a preferred embodiment of the present invention is clearly shown.

In the drawing:

FIGURE 1 is a vertical sectional view partly schematic showing a preferred embodiment of the invention.

FIGURE 2 is a sectional view taken substantially on line 22 of FIGURE 1.

Referring now'to the drawing wherein a preferred embodiment of the invention has been shown, reference numeral generally designates a refrigerant compressor having a refrigerant outlet passage 12 through which the compressed refrigerant is required to pass on its way to the condenser 40 of a conventional refrigerating system. A mufiler element, generally designated by the reference numeral 14, is provided adjacent the compressor outlet 12 for mufiling the noises normally produced by the compressed gas as it flows from the outlet of the compressor. This muffier includes an enlarged stamped sheet metal housing 16 forming a chamber 24 which is arranged to surround a cylindrical baflle element 18 which is arranged in such a manner that the compressed gas leaving the compressor outlet 12 is required to flow throughthe central passage 20 of the baffle element 18. A first pair of outlets 22 are provided in the walls of the baffle element 18 which allow compressed gas to freely flow from the passage 20 into the space 24 within the outer housing 16. The gas entering the chamber 24 leaves the muffler through the bottom outlet passage 26.

During low speed operation of the compressor, the outlets 22 are adequate to pass all of the compressed gas and serve to efliciently muffle the noise of the compressed gas but these two passages are inadequate to efi'iciently handle and muffle the entire volume of compressed gas discharged by the compressor during high speed operation of the compressor. A second pair of outlets 30 are provided as shown and are normally closed by means of a sleeve spring element 32. At high compressor speeds, the spring sleeve 32 yields so as to allow a portion of the compressed gas to flow out through the outlets 30 so as to, in effect, increase the capacity of the mufiler at high compressor speeds. The sleeve spring 32 consists of a split cylindricalspring element which freely surrounds the conduit 20. The spring element is so constructed and arranged that it can expand from the solid line position in which it is shown in FIGURES 1 and 2 to the dotted line position in which it is shown in FIGURE 2. This expansion takes place in response to a predetermined amount of pressure increase within the conduit 20 so as to allow gas to escape through the apertures 30 as well as through the apertures 22.

The compressor 10 is adapted to be used in a refrigcrating system which includes a conventional condenser 40 into which the compressed refrigerant leaving the mufiler outlet 26 is directed. The condensed refrigerant flows from the condenser 40 through a pressure reducing device 42 from whence the refrigerant flows to a conventional evaporator 44 having its outlet connected to the compressor inlet 46, as shown.

By virtue of the above described arrangement, it is apparent that a very simple and inexpensive variable baffle has been provided which effectively serves to vary the total cross sectional area of the ports provided in the baffie as the compressor speed varies.

While the embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted.

What is claimed is as follows:

1. In a silencer for refrigerant compressors and the like, an exhaust collecting chamber, a tubular member projecting into said chamber at one end thereof, said tubular member having a plurality of radial apertures formed therein, a yieldable sleeve surrounding only a portion of said apertures and arranged to close said portion of said apertures at low exhaust pressure and serving to open said portion of apertures in response to an increase in pressure.

2. A muffier comprising, a casing, a conduit extending into said casing, said conduit having a plurality of apertures at least one of which is open at all times, and yield able means for maintaining at least one of said apertures closed during periods of low gas flow through said conduit.

3. A mufiler comprising in combination, a cylindrical casing arranged adjacent the outlet of a compressor or the like so as to receive compressed gas, a conduit extending into said cylindrical casing for receiving said compressed gas, aperture means in the wall of said conduit, and a yieldable spring sleeve yieldably closing only a portioh of said aperture means at low incoming gas pressures and movable to a position to increasingly uncover said aperture means in response to an increase in the pressure of said incoming gas.

4. In combination: an evaporator; a variable speed compressor having an inlet and an outlet; a condenser; refrigerant flow connections between said evaporator, compressor, and condenser including a mufiler adjacent the outlet of said compressor; said mufiler comprising a casing having an inlet and an outlet, a bafile interposed between said inlet and said outlet, said bafile having a plurality of apertures at least one of which is open at all times, and yieldable means maintaining at least one of said apertures closed during periods of low compressor speed and movable to open said last named aperture during periods of high compressor speed.

5. In a refrigerating device including a compressor having a discharge opening for compressed fluid and a condenser, silencing means comprising in combination, an outer shell enclosing a chamber, a perforated tubular member extending into said chamber, passage means establishing a permanently open passage portion and a variably open passage portion for said fluid from said discharge opening into the interior of said chamber, means for varying the eifective size of said variably open passage portion in response to an increase in the quantity of fluid flowing through said discharge opening, and means connecting said chamber to said condenser.

6. A muffler comprising, a casing having an inlet and an outlet, a bafiie in said casing between said inlet and said outlet, means for introducing gas into said casing, 10

said bafiie having a plurality of apertures at least one of 4 which is open at all times, and yieldable means arranged to yieldably close certain of said openings at low inlet pressures and to open at high inlet pressures.

References Cited in the file of this patent UNITED STATES PATENTS 659,456 Smith Oct. 9, 1900 947,431 Grandsagne Jan. 25, 1910 1,368,315 Wygodsky Feb. 15, 1921 2,136,097 Browne Nov. 8, 1938 2,671,466 Conrad Mar. 9, 1954 

